For really serious photo junkies start from manual film SLR and work your way up or else you wont learn anything because in the most recent DSLRs they have made it so easy that you wont learn anything at all because the camera does almost everything for you.

I started with an old Pextax manual film SLR with a manual 50mm lens and rolls of B/W film then I got Nikon F80 film AF SLR with basic AF lenses and color films. Then I moved to Nikon D70s DSLR and now I've Nikon D90 DSLR with pro class lenses.